I don’t know what help this might be, but several years ago, I contacted a native crafter who made clothing and other items from seal skin. I asked them if they had offcuts that they would sell to me for making arrow rests. They offered to send me a one pound bag for $25. In fact, they sent me more than two pounds in several colors.
Unfortunately, I can’t remember who it was.
If you need some for a few bows, pm me. I still have some pieces.
Seal skin is my absolute favourite rest material.
Dave.